Editorial Case Report
Journal of Orthopaedic Case Reports 2014 Jan-Mar;4(1): Page: 35-38
Intraosseous Lipoma of the Femor: Image Findings 1
1
1
2
Hadi Rokni Yazdi , Bahman Rasouli , Ali Borhani , Mohammad Mahdi Noorollahi
What to Learn from this Article? Diagnostic issues related to Intraosseous Lipoma in Long Bones Abstract Introduction: Intraosseous lipoma is a rare benign bone disease. Long and cancellous bones are the most locationsthat can be affected. Almost all lesions were discovered incidentally on imaging modalities that were done during an unrelated investigation. As it is rare, it may be mistaken for nonossifying fibroma, aneurismal bone cyst, simple bone cyst, bone infarct or chondroid tumors. Recently with the high quality imaging modalities such as CT scan and/or MR imaging, the diagnosis of intramedullary lipoma and some other bone lesions can be done without the need for bone biopsy and surgery. Case Report: We’re reporting a rare case of intraosseous lipoma of the distal femur. Plain film radiography showed barely visible medullary expansion and lucency in the distal left femoral diaphysis. The patient underwent further evaluation with computed tomographic (CT) and magnetic resonance Imaging (MRI). According to the MRI and CT scan findings, intraosseous lipoma was confirmed and the need for more diagnostic tests were eliminated. Conclusion: Although Intraosseous lipoma doesn’t have any manifestations clinically but it should be considered in the differential diagnosis of bone pains. MRI has an important role in characterization of soft tissue and bone marrow lesions therefore non-surgical approach for most of the patients with intraosseous lipoma would be beneficial. Keywords: Introsseous lipoma, femur, Magnetic resonance imaging, Computed Tomography. Author’s Photo Gallery
35
Dr. Hadi Rokni Yazdi
Dr. Bahman Rasuli
Dr. Ali Borhani
Dr. MohammadMehdi Noorollah
1 Associate professor, Radiology, Imam Khomeini Hospital, Keshavarz Boulevard, Tehran University of Medical Sciences, Tehran, Iran. 2 Radiologist, Atyeh Hospital, Farahzadi Blvd, Tehran, Iran. Address of Correspondence: Hadi Rokni Yazdi MD, Associate Professor of Radiology, Advanced Diagnostic and Interventional Radiology Research Centre(ADIR), Imam Khomeini Hospital, Keshavarz Boulevard, Tehran University of Medical Sciences, Tehran, Iran. Email: [email protected]
Introduction Intraosseouslipoma is an uncommon benign bone neoplasm [1]. Recently, the number of diagnosed intraosseous lipoma cases has increased which could be due to theactual incidence of the disease [2-5]. Cases with Intraosseous lipomas are often asymptomatic and most of them were diagnosed on multimodality imaging. Patients are usually referred with a complaint that almost always deems to be related to another pathology such as osteoarthritis [5].Radiological or histological findings of intraosseous lipoma is often mistaken for other benign or malignant bone lesions such as enchondroma, fibrous dysplasia, osteoblastoma, bone infarct, bone cyst and chondrosarcoma [2,6-8]. Although plain radiography may show signs of intraosseous lipoma, but its findings can be non-diagnostic and distinction from the other bone lesions would not be possible [9]. However MR imaging or CT scan can suggest the diagnosis and lead to correct decision making [5, 9-11]. Here we are reporting a case of intraosseous lipoma of the distal left femur that was incidentally diagnosed during an unrelated investigation. Case Report A 27-years-old man referred to our medical center with a left thigh pain complaint following a motor vehicle accident. Physical examination
Copyright © 2014 by Journal of Orthpaedic Case Reports Journal of Orthopaedic Case Reports | pISSN 2250-0685 | eISSN 2321-3817 | Available on www.jocr.co.in | doi:10.13107/jocr.2250-0685.146 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
www.jocr.co.in
Yazdi HR et al 1a
1b
Figure 1 (a & b): Anteroposterior and lateral radiograph of the left femur shows barely visible lytic lesion within meta-diaphysis of distal left femur, comparing to the right side (arrow). No periosteal reaction and cortical destruction is noted.
revealed mild tenderness in the left distal thigh without the evidence of palpable mass and soft tissue swelling. Range of motion in both hips and knee joints were within the normal limits. Plain film radiographs [AP and Lateral views] showed a barely visible medullary expansion and lucency in the distal left femoral diaphysis. [fig1a, b]. Computed tomographic [CT] scans of the thigh demonstrated a well-defined fat density mildly expanded intra medullary lesion within the distal two thirds of medullary space of left femur without signs of cortical destruction or periosteal reaction [Fig. 2]. T1-weighted MR images revealed an intramedullary lesion with a greater intensity than that of soft tissue and equal signal intensity to subcutaneous fat [Fig. 3a]. T2-weighted images also showed a high signal intramedullary lesion similar to subcutaneous fat [Fig. 3: b,c]. No abnormal signal intensity was detected in the cortical bone and adjacent soft tissue. On fat suppression proton density MR images, the intramedullary lesion showed a signal drop similar to subcutaneous fat. The inferior border of the lesion in the diaphysis of distal femur and also adjacent meta-epiphysis
3a
3b
Figure 2 : Axial CT scan slice from distal both thighs shows a well-defined lesion with fat attenuation in the central part of left femur( arrow).
showed high signal intensity in favor of post traumatic edema and adjacent bone bruise [Fig. 4]. According to the typical findings of CT and MR images, intraosseous lipoma was diagnosed and the need for histopathalogical examination was eliminated. Discussion Intraosseous lipoma is a very rare primary bone lesion, representing 0.1% to 2.5% of all benign bone tumors [2, 12]. Intraosseous lipoma is usually asymptomatic and the diagnosis is made incidentally[1]. Recently the prevalence of these tumors has been increased, because it is usually asymptomatic and has been misdiagnosed with other primary bone tumors [6, 13]. As symptoms occur, pain, swelling and tenderness are common clinical presentations. Etiology of intraosseous lipoma is not known yet. According to the previous studies, these lesions don't have gender and age preponderance [2, 14]. However a number of other studies have suggested these lesions to be more common in patients between 30-60 years of age [13,15,16,17] and male predominant(two thirds of the lesions)[13,18]. Difference of age range and the absence of specific radiologic and clinical 3c
Figure 3 (a): Acoronal spin-echo T1-weighted MR image (TR/TE, 400/11) shows high signal tubular intra medullary lesion in the distal femur (black arrow) with small relatively low signal in it's distal metaphyseal part (white arrow) whichis probably due to degeneration or edema in the lipoma. . The major part of the lesion consisted of areas of isosignal intensity with subcutaneous fat. (b & c) An axial and sagittal spin-ech and sagittal T2-weighted MR image (TR/TE, 2600/84) shows a hyperintense lesion iso-signal with the subcutaneous fat (black arrow). Journal of Orthopaedic Case Reports | Volume 4 | Issue 1 | Jan-Mar 2014 | Page 35-38
Figure 4 : sagittal fat saturation proton density image, shows reduced signal of the intramedullary mass similar to subcutaneous fat (white arrow). Small mildly high signal area in metaphysis is probably due to degeneration or edema within the lipoma (black arrow).
36
www.jocr.co.in
Yazdi HR et al
37
f indings ma kest he diag nosis of int raoss e ous lipomachallenging. Not only plain radiograph is not a choice diagnostic method for intraosseous lipoma but also can be unremarkable in most cases [9]. In a study of 15 cases with intraosseouslipoma, plain film radiograph was not diagnostic in any of the patients [18]. By contrast the diagnosis of intraosseous lipoma with other imaging modalities such as MRI and CT scan was done without the need for the other subsequent diagnostic tests [8,11,19, 20]. Intraosseous lipomas have specific radiological and histological features and their radiological findings are very well correlated with the histological features [2]. The CT scan demonstration of intraosseous lipomas consists of a lytic lesion with distinct borders and negative Hounsfield unit parallel to adipose tissue. Whereas irregularity of bone cortex and marginal sclerosis surrounding the lesion are frequently seen [16, 22]. MR features of intraosseous lipoma include high signal intensity lesion on both T1 and T2-weighted images similar to that of adipose tissue that which allows differentiation from other bone lesions [10,22].MRI had an important role in confirmation of diagnosis of this lesion prior to histopathological studies[10,19,23,24]. In case of our patient, the hyperintense intramedullary areas on T1-weighted and T2-weighted images and also signal drop in fat suppression image, led to the distinction between intraosseous lipoma and other bone lesions. Recently with the capability of CT-scan or MR imaging in confirming the diagnosis of intramedullary lipoma, the necessity of surgical biopsy for the definite diagnosis has become controversial [25]. Some authors believe that the discretion of fat in the lesion in CT and/or MR images can confirm the benign nature of the lesion and terminate the diagnostic process, because the presence of fat in malignant lesions is extremely rare [5,26,27]. Additionally with a high degree of assurance, distinction of intraosseous lipoma from liposarcoma can be made with the aid of CT-scan and MRI. Absence of usual negative Hounsfield unit and loss of homogeneity can differentiate the liposarcoma from the lipoma. Also with the application of a short repetition time on MR Imaging, liposarcoma (long T1) showed lower intensity than lipoma(short T1) [24]. Asymptomatic lesions don't need surgical treatment and some of them can undergo involution spontaneously [28,29]. If a lesion comes under suspicion for potential malignancy followed by history, clinical and imaging findings, surgical treatment and biopsy must be made. In
our case we did not perform biopsy and radiological followup was approached. Conclusion We reported an uncommon case of symptomatic intraosseous lipoma of the femoral bone following a motor vehicle accident. CT scan or/MRimage findings, showed the benign nature of the lesion by demonstration of fat within it. Histopathological examination must be considered only in cases where clinical and imaging findings are equivocal or Clinical Message Intraosseous lipomasare rare benign bone tumors.Although Intraosseous lipomasdon't have any manifestation clinically but it should be consideredin the differential diagnosis of bone pains whilebone tumors are suspected. Carefulapplication of imaging modalities including MRI and CT scan is necessaryfor the confirmation of the diagnosisthat leads to correct decision making withoutthe needfor more diagnostic procedures such as bone biopsy and surgery.
suggests the existence of a malignant lesion. References 1. Unni KK. Lipoma and liposarcoma. In: Unni KK, editor. Dahlin'sbone tumors.General aspects and data on 11087 cases. Philadelphia:Lippincott-Raven, 1996. pp. 349– 53. 2. Chow LT, Lee KC. Intraosseouslipoma: a clinicopathologic study ofnine cases. Am J SurgPathol 1992;16:401 - 10. 3. Hirata M, Kusuzaki K, Hirasawa Y. Eleven cases of intraosseouslipoma of the calcaneus. Anticancer Res 2001;21:4099103. 4. Goto T, Kojima T, Iijima T, et al. Intraosseouslipoma a clinical studyof 12 patients. J OrthopSci 2002;7:274- 80. 5. Campbell RSD, Grainger AJ, Mangham DC, et al. Intraosseouslipoma: report of 35 new cases and a review of the literature. SkeletalRadiol 2003;32:209 - 22. 6 Milgram JW. Intraosseouslipomas.A clinicopathologic study of66 cases.ClinOrthopRelat Res 1988;231:277 - 302. 7. Williams CE, Close PJ, Meaney J, Ritchie D, Cogley D, Carty AT.Intraosseouslipomas.ClinRadiol 1993;47:348- 50 8. Barcelo M, Pathria MN, Abdul-Karim FW. Intraosseouslipoma: aclinicopathologic study of four cases. Arch Pathol Lab Med 1992;116:947 - 50. 9. Murphey MD, Carroll JF, Flemming DJ, et al. Benign musculoskeletallipomatous lesions. RadioGraphics 2004;24:1433- 66. 10. Blacksin MF, Ende N, Benevenia J. Magnetic resonance imaging ofintraosseouslipomas: a radiologic-pathologic correlation. Journal of Orthopaedic Case Reports | Volume 4 | Issue 1 | Jan-Mar 2014 | Page 35-38
www.jocr.co.in
Yazdi HR et al SkeletalRadiol 1995;24:37- 41.
Choi.Intraosseous Lipoma. J. of Korean Orthop. Assoc. 2003; 38: 526-30
11. Ramos A, Castello J, Sartoris DJ, et al. Osseous lipoma: 22. Boussouga M, Harket A, Et-tai T, Jaafar A, Bousselmame N, Lazrak CTappearance. Radiology 1985;157:615 - 9. K. Lipomeintraosseux du calcan_eus: _a propos d'une observation. Med Chir Pied 23:124–126,2007. 12. Dadjo K. Aumar,Yves B.A. Dadjo, Belkacem Chagar. Intraosseous Lipoma of the Calcaneus: Report of a Case and Review of the 23. Coquerelle P, Cotten A, Flipo RM, Chastanet P, Duquesnoy B, Literature. The Journal of Foot & Ankle Surgery 2013; 52: 360–363. Delcambre B. Intraosseouslipoma: role and limitations of modern imaging techniques. Rev RhumEngl Ed 62:147–150, 1995. 13. Milgram JW. Intraosseouslipomas: radiologic and pathologic manifestations.Radiology 167:155–160, 1988. 24. Reig-Boix V, Guinot-Tormo J, Risent-Martinez F, Aparisi-Rodriguez F, Ferrer-Jimenez R. Computed tomography of intraosseouslipoma of 14. Hart JAL. Intraosseouslipoma. J Bone Joint Surg Br 55:624–632, oscalcis. ClinOrthop221:286–291, 1987. 1973. 25. Dooms GC, Hricak H, Sollitto RA, Higgins CB. Lipomatous tumors 15. Bruni L. The “cockade” image: a diagnostic sign of and tumors withfatty component: MR imaging potential and calcaneumintraosseouslipoma.Rays 11:51–54, 1986. comparison of MR and CT results.Radiology 157:479–483, 1985. 16. Greenspan A, Raiszadeh K, Riley GM, Matthews D. 26. Simpfendorfer CS, Ilaslan H, Davies AM et al: Does the presence of Intraosseouslipoma of the calcaneus. Foot Ankle Int 18:53–56, 1997. focal normal marrow fat signal within a tumor on MRI exclude 17. Abrahim-Zadeh R, Klein RM, Leslie D, Norman A. malignancy? An analysis of 184 histologically proven tumors of the Characteristics of calcaneal boneinfarction: an MR imaging pelvic and appendicular skeleton. Skeletal Radiol, 2008; 37: 797–804. investigation. Skeletal Radiol 27:321–324, 1998. 27. Stacy GS: An analysis of malignant bone tumors for the presence of 18. Appenzeller J, Weitzner S. Intraosseouslipoma of oscalcis: case internal fat-signal-intensity on magnetic resonance examinations. report and reviewof literature of intraosseouslipoma of extremities. Skeletal Radiol, 2007; 36: 355–75. ClinOrthop 101:171–175, 1974. 28. Bagatur AE, Yalcinkaya M, Dogan A, Gur S, Mumcuoglu E, 19. Ketyer S, Brownstein S, Cholankeril J. CT diagnosis of Albayrak M. Surgery isnot always necessary in intraosseouslipoma. intraosseouslipoma of thecalcaneus. J Comput Assist Tomogr Orthopedics 33:33, 2010. 7:546–547, 1983. 29. Weinfeld GD, Yu GV, Good JJ. Intraosseouslipoma of the calcaneus: a 20 Boylan JP, Springer KR, Halpern FP. Intraosseouslipoma of the review andreport of four cases. J Foot Ankle Surg 41:398–411, 2002. calcaneus: a casereport. J Am Podiatr Med Assoc 81:502–505, 1991. 21. Duk Seop Shin, M.D., Eun Seok Kwak, M.D., Joon Hyuk
Conflict of Interest: Nil Source of Support: None
How to Cite this Article: Yazdi HR, Rasouli B, Borhani A, Noorollahi MM. Intraosseous Lipoma of the Femor: Image Findings Journal of Orthopaedic Case Reports. 2014 Jan-Mar;4(1): 35-38
38
Journal of Orthopaedic Case Reports | Volume 4 | Issue 1 | Jan-Mar 2014 | Page 35-38
Journal of Orthopaedic Case Reports 2014 Jan-Mar;4(1): Page: 35-38
Intraosseous Lipoma of the Femor: Image Findings 1
1
1
2
Hadi Rokni Yazdi , Bahman Rasouli , Ali Borhani , Mohammad Mahdi Noorollahi
What to Learn from this Article? Diagnostic issues related to Intraosseous Lipoma in Long Bones Abstract Introduction: Intraosseous lipoma is a rare benign bone disease. Long and cancellous bones are the most locationsthat can be affected. Almost all lesions were discovered incidentally on imaging modalities that were done during an unrelated investigation. As it is rare, it may be mistaken for nonossifying fibroma, aneurismal bone cyst, simple bone cyst, bone infarct or chondroid tumors. Recently with the high quality imaging modalities such as CT scan and/or MR imaging, the diagnosis of intramedullary lipoma and some other bone lesions can be done without the need for bone biopsy and surgery. Case Report: We’re reporting a rare case of intraosseous lipoma of the distal femur. Plain film radiography showed barely visible medullary expansion and lucency in the distal left femoral diaphysis. The patient underwent further evaluation with computed tomographic (CT) and magnetic resonance Imaging (MRI). According to the MRI and CT scan findings, intraosseous lipoma was confirmed and the need for more diagnostic tests were eliminated. Conclusion: Although Intraosseous lipoma doesn’t have any manifestations clinically but it should be considered in the differential diagnosis of bone pains. MRI has an important role in characterization of soft tissue and bone marrow lesions therefore non-surgical approach for most of the patients with intraosseous lipoma would be beneficial. Keywords: Introsseous lipoma, femur, Magnetic resonance imaging, Computed Tomography. Author’s Photo Gallery
35
Dr. Hadi Rokni Yazdi
Dr. Bahman Rasuli
Dr. Ali Borhani
Dr. MohammadMehdi Noorollah
1 Associate professor, Radiology, Imam Khomeini Hospital, Keshavarz Boulevard, Tehran University of Medical Sciences, Tehran, Iran. 2 Radiologist, Atyeh Hospital, Farahzadi Blvd, Tehran, Iran. Address of Correspondence: Hadi Rokni Yazdi MD, Associate Professor of Radiology, Advanced Diagnostic and Interventional Radiology Research Centre(ADIR), Imam Khomeini Hospital, Keshavarz Boulevard, Tehran University of Medical Sciences, Tehran, Iran. Email: [email protected]
Introduction Intraosseouslipoma is an uncommon benign bone neoplasm [1]. Recently, the number of diagnosed intraosseous lipoma cases has increased which could be due to theactual incidence of the disease [2-5]. Cases with Intraosseous lipomas are often asymptomatic and most of them were diagnosed on multimodality imaging. Patients are usually referred with a complaint that almost always deems to be related to another pathology such as osteoarthritis [5].Radiological or histological findings of intraosseous lipoma is often mistaken for other benign or malignant bone lesions such as enchondroma, fibrous dysplasia, osteoblastoma, bone infarct, bone cyst and chondrosarcoma [2,6-8]. Although plain radiography may show signs of intraosseous lipoma, but its findings can be non-diagnostic and distinction from the other bone lesions would not be possible [9]. However MR imaging or CT scan can suggest the diagnosis and lead to correct decision making [5, 9-11]. Here we are reporting a case of intraosseous lipoma of the distal left femur that was incidentally diagnosed during an unrelated investigation. Case Report A 27-years-old man referred to our medical center with a left thigh pain complaint following a motor vehicle accident. Physical examination
Copyright © 2014 by Journal of Orthpaedic Case Reports Journal of Orthopaedic Case Reports | pISSN 2250-0685 | eISSN 2321-3817 | Available on www.jocr.co.in | doi:10.13107/jocr.2250-0685.146 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
www.jocr.co.in
Yazdi HR et al 1a
1b
Figure 1 (a & b): Anteroposterior and lateral radiograph of the left femur shows barely visible lytic lesion within meta-diaphysis of distal left femur, comparing to the right side (arrow). No periosteal reaction and cortical destruction is noted.
revealed mild tenderness in the left distal thigh without the evidence of palpable mass and soft tissue swelling. Range of motion in both hips and knee joints were within the normal limits. Plain film radiographs [AP and Lateral views] showed a barely visible medullary expansion and lucency in the distal left femoral diaphysis. [fig1a, b]. Computed tomographic [CT] scans of the thigh demonstrated a well-defined fat density mildly expanded intra medullary lesion within the distal two thirds of medullary space of left femur without signs of cortical destruction or periosteal reaction [Fig. 2]. T1-weighted MR images revealed an intramedullary lesion with a greater intensity than that of soft tissue and equal signal intensity to subcutaneous fat [Fig. 3a]. T2-weighted images also showed a high signal intramedullary lesion similar to subcutaneous fat [Fig. 3: b,c]. No abnormal signal intensity was detected in the cortical bone and adjacent soft tissue. On fat suppression proton density MR images, the intramedullary lesion showed a signal drop similar to subcutaneous fat. The inferior border of the lesion in the diaphysis of distal femur and also adjacent meta-epiphysis
3a
3b
Figure 2 : Axial CT scan slice from distal both thighs shows a well-defined lesion with fat attenuation in the central part of left femur( arrow).
showed high signal intensity in favor of post traumatic edema and adjacent bone bruise [Fig. 4]. According to the typical findings of CT and MR images, intraosseous lipoma was diagnosed and the need for histopathalogical examination was eliminated. Discussion Intraosseous lipoma is a very rare primary bone lesion, representing 0.1% to 2.5% of all benign bone tumors [2, 12]. Intraosseous lipoma is usually asymptomatic and the diagnosis is made incidentally[1]. Recently the prevalence of these tumors has been increased, because it is usually asymptomatic and has been misdiagnosed with other primary bone tumors [6, 13]. As symptoms occur, pain, swelling and tenderness are common clinical presentations. Etiology of intraosseous lipoma is not known yet. According to the previous studies, these lesions don't have gender and age preponderance [2, 14]. However a number of other studies have suggested these lesions to be more common in patients between 30-60 years of age [13,15,16,17] and male predominant(two thirds of the lesions)[13,18]. Difference of age range and the absence of specific radiologic and clinical 3c
Figure 3 (a): Acoronal spin-echo T1-weighted MR image (TR/TE, 400/11) shows high signal tubular intra medullary lesion in the distal femur (black arrow) with small relatively low signal in it's distal metaphyseal part (white arrow) whichis probably due to degeneration or edema in the lipoma. . The major part of the lesion consisted of areas of isosignal intensity with subcutaneous fat. (b & c) An axial and sagittal spin-ech and sagittal T2-weighted MR image (TR/TE, 2600/84) shows a hyperintense lesion iso-signal with the subcutaneous fat (black arrow). Journal of Orthopaedic Case Reports | Volume 4 | Issue 1 | Jan-Mar 2014 | Page 35-38
Figure 4 : sagittal fat saturation proton density image, shows reduced signal of the intramedullary mass similar to subcutaneous fat (white arrow). Small mildly high signal area in metaphysis is probably due to degeneration or edema within the lipoma (black arrow).
36
www.jocr.co.in
Yazdi HR et al
37
f indings ma kest he diag nosis of int raoss e ous lipomachallenging. Not only plain radiograph is not a choice diagnostic method for intraosseous lipoma but also can be unremarkable in most cases [9]. In a study of 15 cases with intraosseouslipoma, plain film radiograph was not diagnostic in any of the patients [18]. By contrast the diagnosis of intraosseous lipoma with other imaging modalities such as MRI and CT scan was done without the need for the other subsequent diagnostic tests [8,11,19, 20]. Intraosseous lipomas have specific radiological and histological features and their radiological findings are very well correlated with the histological features [2]. The CT scan demonstration of intraosseous lipomas consists of a lytic lesion with distinct borders and negative Hounsfield unit parallel to adipose tissue. Whereas irregularity of bone cortex and marginal sclerosis surrounding the lesion are frequently seen [16, 22]. MR features of intraosseous lipoma include high signal intensity lesion on both T1 and T2-weighted images similar to that of adipose tissue that which allows differentiation from other bone lesions [10,22].MRI had an important role in confirmation of diagnosis of this lesion prior to histopathological studies[10,19,23,24]. In case of our patient, the hyperintense intramedullary areas on T1-weighted and T2-weighted images and also signal drop in fat suppression image, led to the distinction between intraosseous lipoma and other bone lesions. Recently with the capability of CT-scan or MR imaging in confirming the diagnosis of intramedullary lipoma, the necessity of surgical biopsy for the definite diagnosis has become controversial [25]. Some authors believe that the discretion of fat in the lesion in CT and/or MR images can confirm the benign nature of the lesion and terminate the diagnostic process, because the presence of fat in malignant lesions is extremely rare [5,26,27]. Additionally with a high degree of assurance, distinction of intraosseous lipoma from liposarcoma can be made with the aid of CT-scan and MRI. Absence of usual negative Hounsfield unit and loss of homogeneity can differentiate the liposarcoma from the lipoma. Also with the application of a short repetition time on MR Imaging, liposarcoma (long T1) showed lower intensity than lipoma(short T1) [24]. Asymptomatic lesions don't need surgical treatment and some of them can undergo involution spontaneously [28,29]. If a lesion comes under suspicion for potential malignancy followed by history, clinical and imaging findings, surgical treatment and biopsy must be made. In
our case we did not perform biopsy and radiological followup was approached. Conclusion We reported an uncommon case of symptomatic intraosseous lipoma of the femoral bone following a motor vehicle accident. CT scan or/MRimage findings, showed the benign nature of the lesion by demonstration of fat within it. Histopathological examination must be considered only in cases where clinical and imaging findings are equivocal or Clinical Message Intraosseous lipomasare rare benign bone tumors.Although Intraosseous lipomasdon't have any manifestation clinically but it should be consideredin the differential diagnosis of bone pains whilebone tumors are suspected. Carefulapplication of imaging modalities including MRI and CT scan is necessaryfor the confirmation of the diagnosisthat leads to correct decision making withoutthe needfor more diagnostic procedures such as bone biopsy and surgery.
suggests the existence of a malignant lesion. References 1. Unni KK. Lipoma and liposarcoma. In: Unni KK, editor. Dahlin'sbone tumors.General aspects and data on 11087 cases. Philadelphia:Lippincott-Raven, 1996. pp. 349– 53. 2. Chow LT, Lee KC. Intraosseouslipoma: a clinicopathologic study ofnine cases. Am J SurgPathol 1992;16:401 - 10. 3. Hirata M, Kusuzaki K, Hirasawa Y. Eleven cases of intraosseouslipoma of the calcaneus. Anticancer Res 2001;21:4099103. 4. Goto T, Kojima T, Iijima T, et al. Intraosseouslipoma a clinical studyof 12 patients. J OrthopSci 2002;7:274- 80. 5. Campbell RSD, Grainger AJ, Mangham DC, et al. Intraosseouslipoma: report of 35 new cases and a review of the literature. SkeletalRadiol 2003;32:209 - 22. 6 Milgram JW. Intraosseouslipomas.A clinicopathologic study of66 cases.ClinOrthopRelat Res 1988;231:277 - 302. 7. Williams CE, Close PJ, Meaney J, Ritchie D, Cogley D, Carty AT.Intraosseouslipomas.ClinRadiol 1993;47:348- 50 8. Barcelo M, Pathria MN, Abdul-Karim FW. Intraosseouslipoma: aclinicopathologic study of four cases. Arch Pathol Lab Med 1992;116:947 - 50. 9. Murphey MD, Carroll JF, Flemming DJ, et al. Benign musculoskeletallipomatous lesions. RadioGraphics 2004;24:1433- 66. 10. Blacksin MF, Ende N, Benevenia J. Magnetic resonance imaging ofintraosseouslipomas: a radiologic-pathologic correlation. Journal of Orthopaedic Case Reports | Volume 4 | Issue 1 | Jan-Mar 2014 | Page 35-38
www.jocr.co.in
Yazdi HR et al SkeletalRadiol 1995;24:37- 41.
Choi.Intraosseous Lipoma. J. of Korean Orthop. Assoc. 2003; 38: 526-30
11. Ramos A, Castello J, Sartoris DJ, et al. Osseous lipoma: 22. Boussouga M, Harket A, Et-tai T, Jaafar A, Bousselmame N, Lazrak CTappearance. Radiology 1985;157:615 - 9. K. Lipomeintraosseux du calcan_eus: _a propos d'une observation. Med Chir Pied 23:124–126,2007. 12. Dadjo K. Aumar,Yves B.A. Dadjo, Belkacem Chagar. Intraosseous Lipoma of the Calcaneus: Report of a Case and Review of the 23. Coquerelle P, Cotten A, Flipo RM, Chastanet P, Duquesnoy B, Literature. The Journal of Foot & Ankle Surgery 2013; 52: 360–363. Delcambre B. Intraosseouslipoma: role and limitations of modern imaging techniques. Rev RhumEngl Ed 62:147–150, 1995. 13. Milgram JW. Intraosseouslipomas: radiologic and pathologic manifestations.Radiology 167:155–160, 1988. 24. Reig-Boix V, Guinot-Tormo J, Risent-Martinez F, Aparisi-Rodriguez F, Ferrer-Jimenez R. Computed tomography of intraosseouslipoma of 14. Hart JAL. Intraosseouslipoma. J Bone Joint Surg Br 55:624–632, oscalcis. ClinOrthop221:286–291, 1987. 1973. 25. Dooms GC, Hricak H, Sollitto RA, Higgins CB. Lipomatous tumors 15. Bruni L. The “cockade” image: a diagnostic sign of and tumors withfatty component: MR imaging potential and calcaneumintraosseouslipoma.Rays 11:51–54, 1986. comparison of MR and CT results.Radiology 157:479–483, 1985. 16. Greenspan A, Raiszadeh K, Riley GM, Matthews D. 26. Simpfendorfer CS, Ilaslan H, Davies AM et al: Does the presence of Intraosseouslipoma of the calcaneus. Foot Ankle Int 18:53–56, 1997. focal normal marrow fat signal within a tumor on MRI exclude 17. Abrahim-Zadeh R, Klein RM, Leslie D, Norman A. malignancy? An analysis of 184 histologically proven tumors of the Characteristics of calcaneal boneinfarction: an MR imaging pelvic and appendicular skeleton. Skeletal Radiol, 2008; 37: 797–804. investigation. Skeletal Radiol 27:321–324, 1998. 27. Stacy GS: An analysis of malignant bone tumors for the presence of 18. Appenzeller J, Weitzner S. Intraosseouslipoma of oscalcis: case internal fat-signal-intensity on magnetic resonance examinations. report and reviewof literature of intraosseouslipoma of extremities. Skeletal Radiol, 2007; 36: 355–75. ClinOrthop 101:171–175, 1974. 28. Bagatur AE, Yalcinkaya M, Dogan A, Gur S, Mumcuoglu E, 19. Ketyer S, Brownstein S, Cholankeril J. CT diagnosis of Albayrak M. Surgery isnot always necessary in intraosseouslipoma. intraosseouslipoma of thecalcaneus. J Comput Assist Tomogr Orthopedics 33:33, 2010. 7:546–547, 1983. 29. Weinfeld GD, Yu GV, Good JJ. Intraosseouslipoma of the calcaneus: a 20 Boylan JP, Springer KR, Halpern FP. Intraosseouslipoma of the review andreport of four cases. J Foot Ankle Surg 41:398–411, 2002. calcaneus: a casereport. J Am Podiatr Med Assoc 81:502–505, 1991. 21. Duk Seop Shin, M.D., Eun Seok Kwak, M.D., Joon Hyuk
Conflict of Interest: Nil Source of Support: None
How to Cite this Article: Yazdi HR, Rasouli B, Borhani A, Noorollahi MM. Intraosseous Lipoma of the Femor: Image Findings Journal of Orthopaedic Case Reports. 2014 Jan-Mar;4(1): 35-38
38
Journal of Orthopaedic Case Reports | Volume 4 | Issue 1 | Jan-Mar 2014 | Page 35-38
